Abstract: A smoothing structure containing indium is formed between the substrate and the active region of a III-nitride light emitting device to improve the surface characteristics of the device layers. In some embodiments, the smoothing structure is a single layer, separated from the active region by a spacer layer which typically does not contain indium. The smoothing layer contains a composition of indium lower than the active region, and is typically deposited at a higher temperature than the active region. The spacer layer is typically deposited while reducing the temperature in the reactor from the smoothing layer deposition temperature to the active region deposition temperature. In other embodiments, a graded smoothing region is used to improve the surface characteristics. The smoothing region may have a graded composition, graded dopant concentration, or both.

Abstract: LEDs employing a III-Nitride light emitting active region deposited on a base layer above a substrate show improved optical properties with the base layer grown on an intentionally misaligned substrate with a thickness greater than 3.5 &mgr;m. Improved brightness, improved quantum efficiency, and a reduction in the current at which maximum quantum efficiency occurs are among the improved optical properties resulting from use of a misaligned substrate and a thick base layer. Illustrative examples are given of misalignment angles in the range from 0.05° to 0.50°, and base layers in the range from 6.5 to 9.5 &mgr;m although larger values of both misalignment angle and base layer thickness can be used. In some cases, the use of thicker base layers provides sufficient structural support to allow the substrate to be removed from the device entirely.

Abstract: A light emitting device in accordance with an embodiment of the present invention includes a first semiconductor layer of a first conductivity type having a first surface, and an active region formed overlying the first semiconductor layer. The active region includes a second semiconductor layer which is either a quantum well layer or a barrier layer. The second semiconductor layer is formed from a semiconductor alloy having a composition graded in a direction substantially perpendicular to the first surface of the first semiconductor layer. The light emitting device also includes a third semiconductor layer of a second conductivity type formed overlying the active region.

Abstract: A smoothing structure containing indium is formed between the substrate and the active region of a III-nitride light emitting device to improve the surface characteristics of the device layers. In some embodiments, the smoothing structure is a single layer, separated from the active region by a spacer layer which typically does not contain indium. The smoothing layer contains a composition of indium lower than the active region, and is typically deposited at a higher temperature than the active region. The spacer layer is typically deposited while reducing the temperature in the reactor from the smoothing layer deposition temperature to the active region deposition temperature. In other embodiments, a graded smoothing region is used to improve the surface characteristics. The smoothing region may have a graded composition, graded dopant concentration, or both.

Abstract: A smoothing structure containing indium is formed between the substrate and the active region of a III-nitride light emitting device to improve the surface characteristics of the device layers. In some embodiments, the smoothing structure is a single layer, separated from the active region by a spacer layer which typically does not contain indium. The smoothing layer contains a composition of indium lower than the active region, and is typically deposited at a higher temperature than the active region. The spacer layer is typically deposited while reducing the temperature in the reactor from the smoothing layer deposition temperature to the active region deposition temperature. In other embodiments, a graded smoothing region is used to improve the surface characteristics. The smoothing region may have a graded composition, graded dopant concentration, or both.

Abstract: A smoothing structure containing indium is formed between the substrate and the active region of a III-nitride light emitting device to improve the surface characteristics of the device layers. In some embodiments, the smoothing structure is a single layer, separated from the active region by a spacer layer which typically does not contain indium. The smoothing layer contains a composition of indium lower than the active region, and is typically deposited at a higher temperature than the active region. The spacer layer is typically deposited while reducing the temperature in the reactor from the smoothing layer deposition temperature to the active region deposition temperature. In other embodiments, a graded smoothing region is used to improve the surface characteristics. The smoothing region may have a graded composition, graded dopant concentration, or both.

Abstract: LEDs employing a III-Nitride light emitting active region deposited on a base layer above a substrate show improved optical properties with the base layer grown on an intentionally misaligned substrate with a thickness greater than 3.5 &mgr;m. Improved brightness, improved quantum efficiency, and a reduction in the current at which maximum quantum efficiency occurs are among the improved optical properties resulting from use of a misaligned substrate and a thick base layer. Illustrative examples are given of misalignment angles in the range from 0.05° to 0.50°, and base layers in the range from 6.5 to 9.5 &mgr;m although larger values of both misalignment angle and base layer thickness can be used. In some cases, the use of thicker base layers provides sufficient structural support to allow the substrate to be removed from the device entirely.

Abstract: P-type layers of a GaN based light-emitting device are optimized for formation of Ohmic contact with metal. In a first embodiment, a p-type GaN transition layer with a resistivity greater than or equal to about 7 &OHgr;cm is formed between a p-type conductivity layer and a metal contact. In a second embodiment, the p-type transition layer is any III-V semiconductor. In a third embodiment, the p-type transition layer is a superlattice. In a fourth embodiment, a single p-type layer of varying composition and varying concentration of dopant is formed.

Abstract: The present invention relates to electronic devices formed in crystallites of III-V nitride materials. Specifically, the present invention simplifies the processing technology required for the fabrication of high-performance electronic devices in III-V nitride materials.